This application claims the priorities of German application 100 33 190.4, filed Jul. 7, 2000 and German application 100 41 120.7, filed Aug. 22, 2000, the disclosures of which are expressly incorporated by reference herein.
The invention relates to a nozzle for spraying a surface, having a housing with a feeding duct and with an outlet opening for the liquid to be sprayed, as well as having an impact plate for deflecting the jet emerging from the outlet opening.
Spraying nozzles of this type are known, in the case of which, for example, a liquid jet impacts on an impact plate arranged at a distance in front of the outlet opening and is distributed from there in the shape of a fan as a spray jet to the outside. When surfaces are to be cooled, such spraying nozzles are correspondingly arranged at a distance in front of the surface on a holding device. Other devices for cooling surfaces also provide spraying nozzles which are arranged at a distance from the surface and emit, for example, a conical spraying jet in the downward direction onto the surface. In all cases, it is necessary to fasten the spraying nozzles at a corresponding distance in front of the surface to be cooled on a holding device. The necessary distance of the nozzles becomes the larger, the larger the surface to be acted upon. In the case of such constructions, it is always necessary to lay, in addition to the holding devices for the nozzles, also the corresponding piping for feeding the corresponding cooling liquid.
It is an object of the present invention to further develop a nozzle of the initially mentioned type such that a holding device outside the surface and thus also the piping to be laid outside the surface become superfluous.
In the case of a nozzle of the initially mentioned type, preferred embodiments of the invention provides that the outlet opening is situated in the surface to be sprayed and the impact plate is arranged on a piston rod centrally guided in the feeding duct and closes off the outlet opening in one of its end positions, that the impact plate can be adjusted against the force of a restoring spring by the pressure of the liquid into a second end position defined by a stop, and in that, in this second end position, the impact plate is situated at a distance in front of the outlet opening.
As a result of this embodiment, the arrangement of a holding device outside the surface to be sprayed will be superfluous because the surface itself is used for accommodating the nozzle. The feed pipes required for the nozzle can be laid on the side facing away from the surface to be sprayed.
As a further development of preferred embodiments of the invention, the piston rod can penetrate a passage opening of a smaller cross-section than the outlet opening, which passage opening is situated in front of the outlet opening in the flow direction of the liquid, so that the liquid to be sprayed is guided to the outside essentially in the area along the piston rod and is then deflected on the impact plate. In this case, the impact plate can, on its side facing the outlet opening, extend at least in the radially exterior area in a plane perpendicular to the axis of the piston rod, and a rounding can be provided in the transition area between the piston rod and the impact plate, which rounding contributes to the fact that the liquid emerging from the nozzle is guided along the piston rod, is then continuously deflected into a direction extending perpendicular to the original outlet direction and is then deflected again to the surface to be sprayed as a backward-directed spray fan.
As a further development of preferred embodiments of the invention, the stop defining the second end position of the impact plate can be formed by a piston at the end of the piston rod facing away from the impact plate, which piston can be displaced in a guiding cylinder of a predetermined length. This guiding cylinder and the piston guided therein determine the distance of the impact plate from the surface to be sprayed. The piston itself has the purpose of pressing the piston rod as a result of the liquid pressure to the outside so that the impact plate takes up its second end position.
However, the piston can also be used as a resting device for a helical spring which is used as a restoring spring and is arranged around the piston rod and whose second end rests against a guide disk within the feeding duct, which guide disk is used as a guide for the piston rod. In this case, the piston and the guide disk are preferably provided with passage openings for the liquid to be sprayed.
As a further development of preferred embodiments of the invention, the housing can be provided with a flange whose side pointing away from the housing is aligned with the impact plate in its inoperative position. This flange can be inserted in such a manner into the surface to be sprayed that its exterior side aligned with the impact plate coincides with the surface to be sprayed.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.